Digital Waveguide Mesh Modelling of Room Acoustics Surround-sound, Boundaries and Plugin Im.pdf

Proceedings of the COST G-6 Conference on Digital Audio Effects (DAFX-01), Limerick, Ireland, December 6-8, 2001 DAFX-1 DIGITAL WAVEGUIDE MESH MODELLING OF ROOM ACOUSTICS: SURROUND-SOUND, BOUNDARIES AND PLUGIN IMPLEMENTATION Damian T. Murphy, Chris J. C. Newton, and David M. Howard Department of Electronics University of York, Heslington, York, YO10 5DD, UK dtm3@ohm.york.ac.uk ABSTRACT Digital waveguide mesh models have provided an accurate and efficient method of modelling the properties of many resonant structures, including acoustic spaces. 2-D rectilinear and triangular mesh structures have been used extensively in the past to model plates and membranes and as potential analogues to 2-D acoustic spaces. This paper looks at current developments relating to this technique and attempts to highlight potential ways forward for this research. This includes an investigation into the potential suitability of this technique for surround-sound applications and a realtime implementation as a VST plugin. 1. INTRODUCTION The acoustic properties of a real enclosed space can be uniquely defined by measuring the Room Impulse Response (RIR) at a specific listening point for an input signal applied at a given sound source location. Two methods traditionally used for modelling a RIR based on a description of the room geometry, are ray tracing [1] and the image source method [2]. Hybrid or enhanced models based on these techniques also exist [3]. These methods have individual limitations although common to both is the fact that they are only valid for high frequencies. At low frequencies, or for small, enclosed spaces, where the wave-like behaviour of sound and the effects of room resonances or modes are more noticeable these methods are less appropriate. Digital waveguide mesh models have provided an accurate and efficient method of modelling this physically complex system [4], [5], [6], [7], and it is possible to obtain a RIR as the output from such models. This simulation